Sunday, 23 August 2015

T 557/13 - Referral: Mother poisonous for child?

This case refers five questions to the Enlarged Board of Appeal with respect to what is often referred to as partial priority, poisonous divisionals and poisonous priorities. This case has been discussed earlier in this blog, see our post "T 557/13 - Poisonous or nothing wrong?". The opposition decision under appeal relates to a patent that is a divisional from D1 (which is an EP patent enjoying priority from D16). The divisional also claims priority from D16. The Opposition Division decided that claim 1 of the patent of this appeal case does not enjoy the priority from D16 and, thus, the filing date of D1 is the effective date of claim 1. It may be that the opinion of the Opposition Division is now summarized too much, but, according to the Opposition Division is D1 is an Art. 54(3) EPC document because the effective date of D1 is the priority date of D16, and D1 is published after the effective date of claim 1. An additional complication in this case is that claim 1 of the divisional application is a so-termed "generic 'OR'-claim" (see point 8.2.2 of this decision for a definition). Subsequently one could argue that a first portion of claim 1 enjoys priority from D16 and D1 is not an Art. 54(3) EPC document for this first portion, while another second portion of claim 1 does not enjoy priority from D1 and, consequently, the novelty of this second portion must be examined over D1 as an Art. 54(3) EPC document. Furthermore, the parties to the appeal proceedings had a diverging opinion about "Can a parent application of a divisional application be a novelty destroying Art. 54(3) EPC document?".The Board of Appeal could not decide on these subjects because, as extensively discussed in the decision, the case law diverges in different directions. Therefore the Board formulated five questions for the Enlarged Board of Appeal.

Summary of Facts and Submissions

I. The appeal lies from the decision of the opposition division to revoke European patent No. 0 921 183.

II. The patent was granted on European patent application No. 98203458.9, which is a divisional application of European patent application No. 95923299.2, hereinafter "parent application". The latter was filed as international application PCT/EP95/02251 on 8 June 1995 and published as WO 95/33805 A1 (hereinafter D1) on 14 December 1995. The patent and the parent application claim priority from national application GB 9411614.2 (hereinafter D16) filed on 9 June 1994.

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V. In the decision under appeal, the opposition division came to the following conclusions:- The claims as granted were not objectionable under Article 123(2) or 76(1) EPC.- The subject-matter of Claim 1, resulting from a generalisation of a more specific disclosure in D16, regarding the nature of the compound to be used as a cold flow improver, did not represent the same invention as that set out in D16. The priority claimed was thus not valid for the whole scope of Claim 1. Moreover, referring to opinion G 2/98 (OJ EPO 2001, 427, Reasons, 4, 6.6 and 6.7), the opposition division concluded that the "intermediate generalisation in granted Claim 1 with respect to the disclosure of priority document D16 does not give rise to the claiming of a limited number of clearly defined alternative subject-matters" and thus that the "subject-matter of Claim 1 was only entitled to the filing date of 08.06.1995". This finding was held to be in line with decisions T 665/00 of 13 April 2005, T 1877/08 of 23 February 2010 and T 1496/11 of 12 September 2012.- Although the patent met the requirements of Article 76(1) EPC, it did not enjoy the priority date of parent application D1, which thus was state of the art under Article 54(3) EPC. In this respect, reference was made to decision T 1496/11 (Reasons, 2.1 and 3).- Consequently, the subject-matter of Claim 1 as granted lacked novelty under Article 54(3) EPC in view of the use of the cold flow improver of Example 1, disclosed identically in D16 and D1. The embodiment described in D1 was held to be "entitled to the claimed priority date of 09.06.1994", whereas granted Claim 1 was held to be "only entitled to the filing date of 08.06.1995".

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Reasons for the Decision

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Novelty: Claim 1 and the disclosure of parent application D1

3. Subject-matter of Claim 1
The features of Claim 1 (Point III, supra) can be grouped as follows:
(i) features relating to the use: "The use of a cold flow improver" (i.e. the use of a compound as a cold flow improver) "to enhance the lubricity of a fuel oil composition";
(ii) features defining the compound used as a cold flow improver: "oil soluble polar nitrogen compound carrying two or more substituents of the formula -NR**(13)R**(14), where R**(13) and R**(14) each represent a hydrocarbyl group containing 8 to 40 carbon atoms provided that R**(13) and R**(14) may be the same or different, one or more of which substituents may be in the form of a cation derived therefrom";
(iii) features defining the fuel oil composition to be enhanced in lubricity: "a fuel oil composition having a sulphur content of at most 0.05% by weight"; and,
(iv) features defining the concentration of the cold flow improver upon use: "wherein from 0.001 to 1% by
weight of the cold flow improver based on the weight of the fuel is present".

4. Subject-matter of D1 cited against Claim 1

4.1 As indicated in the decision under appeal, D1 discloses at least one specific use falling within the generic terms of Claim 1. This is not in dispute.

4.2 As regards the nature of the flow improver (group 3(ii) supra), D1 (page 19) discloses several examples of "additives used", "Example 1" reading as follows: "A polar nitrogen compound, an N,N-dialkylammonium salt of 2-N'N'-dialkylamidobenzoate, the product of reacting one mole of phthalic anhydride and two moles of di(hydrogenated tallow)amine." The alkyl substituents of this compound, which comprises a dialkylammonium cation, originate from tallow, a natural fat consisting almost entirely of a mixture of glyceryl esters of C14, C16 and C18 fatty acids. The alkyl substituents are thus "hydrocarbyl groups containing 8 to 40 carbon atoms" within the meaning of Claim 1. The compound disclosed in Example 1 of D1 is thus a mixture of compounds representing one of many conceivable alternative flow improvers falling within the generic definition according to Claim 1. This is also reflected by the fact that dependent Claim 7 (point III, supra) refers specifically to this compound defined as a reaction product.

4.3 The use to which this cold flow improver compound is put (group 3(i) supra) according to D1 (see claims 1, 14 and 15, page 1, penultimate paragraph) is the same as that according to Claim 1. This is apparent from the following parts of D1 in particular:
- page 17: "various additives were tested in Fuels I, II and III";
- page 18, last paragraph: "various additives were used in the numbered examples, the results and the treat rates in ppm by weight of active ingredient based on the weight of the fuel, being given in the Tables"; and
- page 21: "Results (Fuel I)", Example 1 and "... all flow improvers enhance lubricity".

4.4 As regards group 3(iii) supra, D1 (page 17) discloses the use of the oil-soluble polar nitrogen compound of Example 1 for enhancing the lubricity of "Fuel I", which is "a Class 1 diesel fuel commercially available in Sweden" having a sulphur content of 0.001% by weight, i.e. within the range of "at most 0.05% by weight" prescribed by Claim 1.

4.5 As regards group 3(iv) supra, according to page 21 of D1 (first data row in the table, Example 1) the compound of Example 1 was tested using a "treat rate" of 1334 ppm (weight of active ingredient based on the weight of the fuel; see D1, page 18, last paragraph). This treat rate value (0.1334% by weight) falls within the concentration range of "from 0.001 to 1%" defined in Claim 1 at issue. Still according to page 21 of D1 (paragraph between the two tables), the measured wear reduction was an indication of an enhanced lubricity.

4.6 Summing up, D1 discloses the use of an oil-soluble polar nitrogen cold flow improver compound which is covered by the generic chemical definition according to Claim 1, for enhancing the lubricity of a fuel with a sulphur content as defined in Claim 1, at a concentration within the range prescribed by Claim 1.

Novelty objection based on D1

5. D1 as potential state of the art under Article 54(3) EPC

European parent application D1 was published after the (deemed) filing date of the divisional application on which the patent was granted. It is not in dispute that for the parent application, published under the PCT as D1, the requirements of Articles 54(4) and 158(2) EPC 1973 are met.

6. Further conditions to be met

For D1 to be novelty-destroying under Article 54(3) EPC, the following three conditions would also have to met:(a) the relevant subject-matter disclosed in D1 (4.6, supra) enjoys the priority date of D16;(b) the subject-matter of Claim 1 alleged to lack novelty over D1 does not enjoy the priority date of D16; and(c) D1 can indeed be considered to be a (colliding) European application within the meaning of Article 54(3) EPC, even though it is the parent application of the divisional application on which the patent in suit was granted.

7.1 Both the patent and parent application D1 claim the priority of earlier national application D16. The opposition division held (decision, point 3.2, second paragraph, first sentence) that D16 (page 20) identically disclosed not only the use of the additive compound of Example 1 of D1 for the same purpose, but also the characteristics of the fuel in terms of its sulphur content (page 19) and the test results in terms of treat rate and enhanced lubricity (page 22). Hence, the use of the polar nitrogen compound of Example 1 as disclosed in D1 was entitled to priority from D16.

7.2 In its communication of 26 November 2014 (points 4.1.1 to 4.1.3), the Board questioned the identity of the uses disclosed in D16 and D1, respectively, especially regarding the sulphur content of the fuel treated and the treat rate in ppm. At the oral proceedings the appellant overcame the Board's concerns by indicating the following:

7.2.1 The sulphur content of "0.01 wt%" mentioned on page 19, line 15, of D16 was an evident error. The additive of Example 1 was tested in a "Class 1 diesel fuel commercially available in Sweden" (page 19, lines
10 - 11). According to D16 itself (page 2, first full paragraph), such a fuel had a sulphur level below
0.001 wt%. This was also generally known, as evidenced by e.g. document
D4: A.M. Kulinowski et al., "Diesel Fuel Additives to Meet Worldwide Performance and Emissions Requirements", SAE Technical Paper 932737, 1993, in particular page 1, right column, second full paragraph and table I on page 2.

7.2.2 Furthermore, there was no difference between the treat rates reported in D16 and D1, respectively. Given that the treat rates in D16 referred to the concentrations of the additive composition in the fuel, whereas in D1 the treat rates referred to the concentrations of only the active ingredient of the additive composition, the latter concentrations were smaller in value. The identity of the treat rates was apparent from the identical wear value of 254 µm reported in D1 and D16. Hence, D16 and D1 differed only in terms of how the same concentration of active additive was expressed.

7.2.3 At the oral proceedings, the respondent expressly confirmed the correctness of these indications and of the conclusion that the uses of the compound according to Example 1 as described in D16 and D1 were the same.

7.3 Hence, the Board has no doubt that the use of the compound according to Example 1 as described in D16 and in D1 is indeed one and the same, also in respect of the sulphur content of the fuel and the additive concentration (treat rate), and that, consequently, this use enjoys priority from D16.Condition (a) under 6, supra is thus met.

8.1.1 It is common ground between the parties that Claim 1 generically encompasses, inter alia, alternative subject-matters which are not disclosed in priority document D16 but result from generalisations of subject-matter which is disclosed in D16.

8.1.2 According to the parties, Claim 1 contains two such generalisations:
i) Regarding the oil-soluble polar nitrogen compounds to be used as a cold flow improver, D16 (see e.g. paragraph bridging pages 10 and 11) discloses the substituents ?NR**(13)R**(14) as defined in Claim 1, but exclusively as substituents of amine salts or amides made from specific starting materials (see D16, claim 15). The broader definition of the compounds to be used according to Claim 1 amounts to a generalisation of the more specific disclosure of such compounds in D16.
ii) Whereas priority document D16 (see e.g. claim 20) discloses a range of 0.01 to 1% by weight of the cold flow improver concentration based on the weight of the fuel, Claim 1 defines the broadened range of 0.001 to 1% by weight. This broadened range represents a further generalisation of the more specific disclosure of D16.
The Board observes that, in this analysis, the parties appear to have referred to the information contained in claims 2, 14, 15 and 20 of D16.

8.1.3 If, however, reference is made to the specific use of the compound of Example 1 invoked as being novelty-destroying for the subject-matter of Claim 1, the following three generalisations are contained in Claim 1, compared to the priority document:
i) The specific oil-soluble polar nitrogen compound of Example 1 of D16, namely the N,N-dialkylammonium salt of 2-N'N'-dialkylamido-benzoate, the product of reacting one mole of phthalic acid anhydride and two moles of di(hydrogenated tallow)amine, has been generalised to an "oil soluble polar nitrogen compound carrying two or more substituents of the formula -NR**(13)R**(14), where R**(13) and R**(14) each represents a hydrocarbyl group containing 8 to 40 carbon atoms provided that R**(13) and R**(14) may be the same or different, one or more of which substituents may be in the form of a cation derived therefrom";
ii) the specific treat rate (concentration of polar nitrogen compound) illustrated in the use of the priority document, namely, if expressed as an active ingredient, 1334 ppm (0.1334% by weight), has been generalised to "wherein from 0.001 to 1% by weight of the cold flow improver based on the weight of the fuel is present"; and
iii) the specific Fuel I, which is a Class 1 diesel fuel commercially available in Sweden and having a sulphur content of 0.001% by weight, has been generalised to "a fuel oil composition having a sulphur content of at most 0.05% by weight".

8.1.4 The use of the compound according to Example 1 as disclosed in D1 is identically described in the divisional application as filed and in the patent. This use represents one alternative embodiment having all the cumulative features (see point 4.6 supra) of the use defined in broader terms in generic Claim 1, This is also evident from dependent Claim 7, which is expressly directed to the use of the specific compound according to Example 1.

8.2 Partial priority - generic "OR"-claims - terminology

8.2.1 For the purposes of the present decision, the expression "partial priority" is used by the Board in a narrow sense (cf. Schricker (D29), point II.1, second paragraph; Memorandum, paragraph 38), to refer to the situation in which part of the subject-matter of a claim is entitled to the priority date of a single earlier application, whereas the remaining subject-matter is entitled only to the filing date of the subsequent European patent application.

8.2.2 For the purposes of the present decision, a "generic 'OR'-claim" is a claim directed to subject-matter defined by one or more generic expressions, such as a chemical formula, a continuous range of numerical values or a functional definition, or otherwise. Such a generic "OR"-claim encompasses, without spelling them out, alternative subject-matters having all the features of the claim.

8.2.3 Acknowledging entitlement to partial priority for such a generic "OR"-claim to the extent that it encompasses alternative subject-matter disclosed directly, or at least implicitly, and unambiguously, in the priority document means that this alternative subject-matter enjoys the claimed priority date as its effective filing date.

8.3 Opposing views of the parties on partial priority
The parties disagreed as regards the priority date(s) attributable to the subject-matter(s) of Claim 1.

8.3.1 The appellant took the view that partial priority had to be acknowledged for Claim 1 to the extent that it encompassed, as one of a plurality of alternatives, the use of the compound of Example 1 as described in both D1 and the patent, i.e. precisely the use considered by the respondent to be novelty-destroying. More particularly, it argued that applying the approach set out in T 1222/11, the criteria indicated in G 2/98 (Reasons, 6.7) were met.

8.3.2 By contrast, the respondent argued that Claim 1 was not entitled to priority since, due to the generalised wording of Claim 1, the claimed invention was not the same as that disclosed in priority document D16. Not even partial priority could be acknowledged because Claim 1 did not spell out any alternatives. As regards the applicability of the criteria indicated in G 2/98 (Reasons, 6.7), it was true that the case law was divergent.

8.4 Decision on novelty potentially dependent on approach to assessing entitlement to partial priorityRegarding condition (b) under 6, supra, the Board thus takes the view that the decision on novelty of the subject-matter of Claim 1 may depend on what approach is adopted in assessing entitlement to partial priority for a generic "OR"-claim.The concrete question to be resolved here is whether Claim 1 enjoys partial priority to the extent that the use of the product of Example 1 as disclosed in D16 is encompassed by the more generic definition of Claim 1, rather than being spelt out in it. The matter of the proper approach to be adopted for this purpose will be considered in depth in the further course of these Reasons.

The Board merely notes at this point that should the respondent's view on partial priority turn out to be correct, the parties' arguments as to Articles 76(1) and/or 54(3) EPC regarding the possibility of a collision between the patent and its parent application D1 would also have to be assessed before a final decision on novelty can be taken with respect to Claim 1.

Pursuant to Article 112(1)(a) EPC, "in order to ensure uniform application of the law, or if a point of law of fundamental importance arises ... the Board of Appeal shall, during proceedings on a case and either of its own motion or following a request from a party to the appeal, refer any question to the Enlarged Board of Appeal if it considers that a decision is required for the above purposes".
The Board is of the opinion that the conditions laid down in Article 112(1)(a) EPC for a referral of questions concerning, on the one hand, partial priority, and, on the other, the applicability of Article 54(3) EPC to members of the same European parent/divisional family are met, for the following reasons.

17. Questions concerning partial priority

17.1 Preliminary remark - determination of priority dates
Generally speaking, in proceedings before the EPO, the validity of a claim to priority is only assessed if state of the art made available to the public on or after the priority date claimed is potentially novelty-destroying or relevant to inventive step for at least some of the subject-matter claimed. Then, the priority dates attributable respectively to the claimed subject-matter under attack and, if necessary, to the cited state of the art, need to be established.

17.2 Requirements of Article 112(1)(a) EPC

17.2.1 Requests of the parties
Both parties stated that they considered it expedient to refer questions concerning partial priority in cases of generic "OR"-claims, invoking inter alia the fundamental importance of priority-related issues and divergences in the case law. Among the questions submitted by the parties, those relating to partial priority were ranked first.

17.2.2 Point of law of fundamental importanceThe right of priority being one of the cornerstones of the patenting system, the Board considers that clarification of issues arising in the present connection is of fundamental importance. As argued by the appellant, the way in which entitlement to priority is assessed in cases of generic "OR"-claims is of great practical importance for claim drafting and filing strategies.The Board has also become aware of another pending appeal case (T 624/14-3402, concerning European patent No. 2 157 457) in which a request for referral of questions regarding priority of a generic "OR"-claim has been made (cf. submission of the respondent dated 30 October 2014). As in the present case, subject-matter disclosed in the parent application has been invoked as novelty-destroying under Article 54(3) EPC for the subject-matter of a claim of the patent granted on a divisional application.Attention is also drawn to the following further publications which reflect the importance of the issue of partial priority for the interested circles and the controversial nature of the debate:D30: D. Pearce et al., "Opposing views on partial priority"; CIPA, December 2013, pages 716 to 720;D31: M. Lawrence, "The Doctrine of Partial and Multiple Priorities, especially from the standpoint of Toxic Priority"; epi information, 1/2015, pages 23 to 35.

17.2.3 Divergences in the jurisprudenceAs apparent from the analysis (supra) of the jurisprudence before and after G 2/98, the law has not been applied uniformly in the assessment of entitlement to partial priority for generic "OR"-claims. In particular, after G 2/98 two divergent approaches have developed, both of which differ from that before G 2/98. These latter two approaches have relied upon different interpretations of the proviso in the last sentence of G 2/98 (Reasons, 6.7).i) Pre-G2/98Partial priority was acknowledged for a generic "OR"-claim to the extent that it encompassed subject-matter(s) directly, or at least implicitly, and unambiguously disclosed in the priority document (see T 85/87, T 352/97 and T 395/95, supra). The effective date of the subject-matter encompassed as an alternative by the claim and targeted by the cited state of the art was established based on a comparison of the claim with the content of the priority document. Consequently, the same European patent application could, for instance, be cited as state of the art under Article 54(3) EPC against subject-matter generically encompassed by the claim and disclosed in the priority document, and under Article 54(2) EPC against other parts of the claim (T 395/95). The Board observes that these decisions did not rely on an analysis of a generic "OR"-claim in terms of the number and the clarity of the alternative subject-matters it encompassed, including those not disclosed in the priority document.ii) G 2/98The Enlarged Board did not take issue in G 2/98 with the aforementioned approach of the earlier decisions acknowledging partial priority. In point 6.7 of the Reasons, with reference to the Memorandum, it considered that "[t]he use of a generic term or formula in a claim for which multiple priorities are claimed in accordance with Article 88(2), second sentence, EPC is perfectly acceptable under Articles 87(1) and 88(3) EPC, provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters". However, neither in the Reasons, 6.7, nor elsewhere in G 2/98 is there an express reference to a generic "OR"-claim for which partial priority is claimed. According to the appellant, the applicability of the proviso "provided it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" (hereinafter "the proviso in G 2/98") as a legal test for entitlement to partial priority for a generic "OR"-claim appears to be questionable. Moreover, as also pointed out by the parties, G 2/98 does not contain any further explanation of the meaning to be given to the criteria "limited number" and "clearly defined alternative subject-matters". It does not appear to be expressly indicated in G 2/98 whether all or only some of the different types of generic "OR"-claims analysed the Memorandum with respect to examples a), b) and c) would actually meet these criteria and therefore be entitled to partial priority (emphasis by the Board).iii) Post-G 2/98- The pre-G 2/98 approach appears still to have been used, in some instances without even a reference to G 2/98 (cf. T 135/01, supra), or without express consideration of whether the claim, to the extent that it also encompasses subject-matter(s) not disclosed in the priority document and/or not under attack, complies with the proviso in G 2/98.- According to a first post-G 2/98 approach (cf. T 1127/00, T 1877/08 and T 476/09, supra), the boards have refused partial priority with reference to the criteria of the proviso in G 2/98, without however expressly considering the comparable examples of the Memorandum, i.e. examples a), concerning broadening of chemical formulae, and b), concerning broadening of a concentration range. In Nestec SA v Dualit Ltd, supra, the proviso in G 2/98 was also applied as a precondition to be met in order to accord partial priority. Even partial priority was denied because the further alternatives encompassed by the claim but not disclosed in the priority document could not be distinguished clearly enough.- In the second post-G 2/98 approach (cf. T 1222/11 and T 571/10), the proviso in G 2/98 also appears to have been considered as a test for entitlement to partial priority, but to have been interpreted differently from the first approach (T 1127/00, T 1877/08 and T 476/09). This second approach does not require the "clearly defined alternative subject-matters" to be spelt out in the claim. Rather, it suffices to be able to conceptually identify a limited number of such alternative subject-matters by comparing the generic "OR"-claim with the priority document. In this way partial priority may be acknowledged for the alternative subject-matter(s) disclosed in the priority document. The remaining subject-matter(s) of the generic "OR"-claim are treated, in toto, as forming one alternative.The board has also become aware of decision T 2406/10 of 13 January 2015, which did not acknowledge partial priority, with reference to the proviso in G 2/98 and emphasis put on the "limited number" criterion (Reasons, 3.2.2). The second post-G 2/98 approach of the recent decisions T 1222/11 and T 571/10 was not followed. Thus there continues to be a lack of convergence in the jurisprudence which underlines the expediency of referring the matter to the Enlarged Board.

17.2.4 Necessity for a decision by the Enlarged BoardIn the present case, different results in terms of partial priority and, hence, novelty, will be arrived at depending on which of the different approaches mentioned above is applied:i) Applying the pre-G 2/98 approach (of e.g. T 85/87; T135/01) could result in accepting partial priority for Claim 1 to the extent that it covers the specific use disclosed in priority document D16. According to this approach, there would be no need to assess how clearly the alternative subject-matters not disclosed in the priority document can be distinguished and counted.ii) If, instead, either of the post-G 2/98 approaches were taken, the finding on partial priority would appear to depend on how the criteria according to the proviso in G 2/98 are applied:- The first, and literal, approach could lead to denying partial priority for Claim 1, given that it encompasses a practically unlimited number of alternative compounds, which are not spelt out in it. The two broadenings in the form of continua of numerical values could further complicate the identification of clearly distinguishable alternatives within Claim 1.- The second, conceptual or notional, approach could, however, like the pre-G 2/98 approach, result in acknowledging partial priority for Claim 1 to the extent that it encompasses the use of the compound of Example 1 as disclosed in priority document D16.Clarification as to the proper approach to be adopted is therefore needed for the present case.

17.3 Formulation of the questionsReferral questions 1 to 4 have been framed in terms which reflect the fundamental importance of issues of partial priority, which can arise whenever there is state of the art potentially relevant under either Article 54(3) or 54(2) EPC, and not only in situations falling under what has come to be referred to as "toxic priority", or "poisonous divisionals" (present case).The questions also address the issues of- whether the proviso in G 2/98 is actually applicable at all to the assessment of entitlement to partial priority for generic "OR"-claims, as opposed to claims involving multiple priorities (cf. also T 1222/11, Reasons, 11.5.1; D25, page 17, left column, lines 22 - 35), and- if it is applicable, whether all conceivable alternatives encompassed by the generic "OR"-claim which are not disclosed in the priority document can be considered in toto as one alternative, as was the approach in T 1222/11, Reasons, 11.5.5, and T 571/10, Reasons, 4.5.9 and 4.9.14 (cf. also D25, page 18, right column, penultimate sentence, lines 15-19).

18. Question concerning Article 54(3) EPC

18.1 Requirements of Article 112(1)(a) EPC

18.1.1 Requests of the parties
In accordance with the parties' requests, the Board accepts that, if the Enlarged Board of Appeal were to conclude that partial priority may be refused in respect of subject-matter encompassed as an alternative by a generic OR-claim and disclosed in the priority document (cf. question 1 infra), it could become decisive for the present case to know whether parent application D1 could be opposed as state of the art under 54(3) EPC to Claim 1 of the divisional patent in suit.

18.1.2 Point of law of fundamental importanceThis question of the applicability of Article 54(3) EPC in situations of potentially colliding European parent and divisional applications is closely linked to the preceding ones, as it also involves priority issues. Indeed, two European applications of a same parent/divisional family could only collide where priority is claimed from an earlier application. Otherwise, parent and divisional applications will necessarily share, as their effective date, the date of filing of the parent application (Article 76(1) EPC). Hence, the Board considers the applicability of Article 54(3) EPC also to be a point of law of fundamental importance, which has far-reaching practical consequences, for instance in cases where a divisional is filed in response to a lack of unity objection.

18.1.3 Conflicting standpointsThe Board is only aware of decision T 1496/11, supra, relied upon by the opposition division in the decision under appeal, which applied Article 54(3) EPC in a situation of this type (divisional application cited against parent patent). This decision has attracted considerable attention from the interested circles and the controversial nature of the debate on this question is evident from the recent spate of publications, including D20 (last four paragraphs), D21 (points 3.8 to 3.10), D22, D23, D27 (points II.1, II.2 and IV), and D31 (point 1.6.6 and footnote 37).The following arguments in particular have been invoked by the parties and in the literature as regards the applicability of Article 54(3) EPC in this context:i) Arguments in favour- Neither the wording of Article 54(3) EPC itself, nor that of Article 55 EPC concerning non-prejudicial disclosures, rules out that members of a European parent/divisional family may be considered as state of the art under Article 54(3) EPC in respect of each other.- Such an exclusion would provide an unjustified advantage to applicants choosing to file a divisional application from a parent application claiming a priority from an earlier application, compared to those filing parallel European applications claiming priority from the same earlier application.- A European divisional application benefiting from the priority of an earlier application is a European application citable under Article 54(3) EPC, since according to the case law of the boards of appeal, parent and divisional applications are independent of each other (cf. G 1/05, T 441/92, T 1177/00).ii) Arguments against- The legislator did not foresee that the filing of a divisional application could create, retroactively, (fictional) state of the art pursuant to Article 54(3) EPC which would have an earlier priority than, and therefore be citable against, its parent application.- The position that European applications belonging to a parent/divisional family cannot collide under Article 54(3) EPC also appears to be reflected in"Europäisches Patentübereinkommen", Münchner Gemeinschaftskommentar, 8th edition, January 1986, Article 76(1) / Bossung, Notes 131 to 134.- Moreover, it is perceived to be counter to the provisions of the Paris Convention (see also e.g. D25, page 16, bridging paragraph).- A European divisional application is not citable under Article 54(3) EPC against the parent, in view of their special relationship: the root subject-matter is the same, the divisional may not comprise added matter compared to its parent and it is deemed to have been filed on the same day as the parent application and shall enjoy any right of priority (Article 76(1) EPC).

18.1.4 Observations of the Boardi) The same special relationship does not exist in other situations of potential collision between two related European applications, namely between parallel European applications claiming priority from one and the same earlier application (as in T 571/10), or between a European application and its European priority application (as in T 1443/05), the latter situation sometimes being referred to as "toxic" or "poisonous priority".ii) Although issues of priority, divisional applications and/or the purpose of Article 54(3) EPC were addressed by the Enlarged Board of Appeal in G 3/93 (OJ EPO, 1995, 18), G 2/98 (Reasons, 8.1, last paragraph), G 1/03 (OJ EPO, 2005, Reasons, 2.1 to 2.1.3), and G 1/05 (Reasons, 4.3), these decisions/opinions are silent on the specific question whether a parent and any divisional stemming from it may be considered as state of the art under Article 54(3) EPC in respect of each other.

18.2 Formulation of the questionThe Board has formulated the question in broader terms than suggested by the parties, considering that potential collisions under Article 54(3) EPC could occur between any two members of a European parent/divisional family.

19. No referral question concerning Article 76(1) EPC

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Order

For these reasons it is decided that:

The following questions are referred to the Enlarged Board for decision:

1. Where a claim of a European patent application or patent encompasses alternative subject-matters by virtue of one or more generic expressions or otherwise (generic "OR"-claim), may entitlement to partial priority be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, or at least implicitly, and unambiguously, in the priority document?

2. If the answer is yes, subject to certain conditions, is the proviso "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" in point 6.7 of G 2/98 to be taken as the legal test for assessing entitlement to partial priority for a generic "OR"-claim?

3. If the answer to question 2 is yes, how are the criteria "limited number" and "clearly defined alternative subject- matters" to be interpreted and applied?

4. If the answer to question 2 is no, how is entitlement to partial priority to be assessed for a generic "OR"-claim?

5. If an affirmative answer is given to question 1, may subject-matter disclosed in a parent or divisional application of a European patent application be cited as state of the art under Article 54(3) EPC against subject-matter disclosed in the priority document and encompassed as an alternative in a generic "OR"-claim of the said European patent application or of the patent granted thereon?